Mahan S M, Waghela S D, McGuire T C, Rurangirwa F R, Wassink L A, Barbet A F
Department of Infectious Diseases, University of Florida, Gainesville 32611.
J Clin Microbiol. 1992 Apr;30(4):981-6. doi: 10.1128/jcm.30.4.981-986.1992.
The DNA probe pCS20, which was cloned from the DNA of the Crystal Springs heartwater strain from Zimbabwe, cross-reacted with DNAs of heartwater strains from all endemic areas, including four heartwater strains from Zimbabwe, two strains from South Africa, one strain from Nigeria, and the Gardel strain from the Caribbean island of Guadeloupe. By nucleic acid hybridization, the pCS20 DNA probe detected Cowdria ruminantium DNA in all DNA preparations made from plasma samples from infected sheep before and during the febrile reaction. Synthetic oligonucleotides were prepared for amplification of specific C. ruminantium DNA sequences by the polymerase chain reaction (PCR). Amplification of two DNA products (181 and 279 bp) from pCS20 DNA and C. ruminantium genomic DNA of heartwater strains was demonstrated. In contrast, amplification of these products or any other products was not possible from genomic DNAs of Anaplasma marginale, Babesia bigemina, Trypanosoma brucei brucei, Escherichia coli, and bovine endothelial cells. The cross-reactivities of the 32P-labeled PCR products with genomic DNAs from several heartwater strains were similar to those with the pCS20 DNA probe. A nucleic acid-based test that uses hybridization assays and PCR provides a sensitive method for the detection of heartwater in both animals and ticks and has applications in epidemiological studies for the disease, which may allow for improved disease control.
DNA探针pCS20是从津巴布韦水晶泉心水病株的DNA中克隆出来的，它能与所有疫区心水病株的DNA发生交叉反应，这些疫区包括来自津巴布韦的4个心水病株、来自南非的2个病株、来自尼日利亚的1个病株以及来自加勒比海瓜德罗普岛的加德尔病株。通过核酸杂交，pCS20 DNA探针在发热反应之前和期间从感染绵羊血浆样本制备的所有DNA制剂中检测到反刍动物考德里氏体DNA。制备了合成寡核苷酸用于通过聚合酶链反应（PCR）扩增反刍动物考德里氏体的特定DNA序列。证明了从pCS20 DNA和心水病株的反刍动物考德里氏体基因组DNA中扩增出两种DNA产物（181和279 bp）。相比之下，从边缘无浆体、双芽巴贝斯虫、布氏布氏锥虫、大肠杆菌和牛内皮细胞的基因组DNA中无法扩增出这些产物或任何其他产物。32P标记的PCR产物与几种心水病株基因组DNA的交叉反应性与pCS20 DNA探针的交叉反应性相似。一种基于核酸的检测方法，使用杂交分析和PCR，为检测动物和蜱中的心水病提供了一种灵敏的方法，并在该疾病的流行病学研究中有应用，这可能有助于改善疾病控制。
